Sound box for sound-reproducing machines



May 8, 1923. 1,454,297

w. SPOFFORTH SOUND BOX FOR SOUND REPRODUCING MACHINES Filed 001:. 17 1919 N YEA/727E.

Patented May 8, 1923.

7 seem) BOX Fen sounn-nnrnonucine ivincnnvns.

Application filed October17, 1919. ser al at; 231,433.

To all whom it may concern." v

Be it known that; I, l/VALTER SroFFoR'rH,

a subject of GreatBritain,residin at St.

Paul, in the county of Ramsey and State of Minnesota, have invented new and useful Improvements in'SoundBoxes for Sound- Reproducing Machines, of which the following is a specificatio-in I This invention relates to improvements in sound boxes for sound reproducing machines, the primary object being to amplify sound and to produce clearer reproduction thereof than heretofore. A further object is topro- Vide a sound box whichperforms the above functions etficiently and by simple and effective construction. With these andother objects in view my invention comprises the features of construction and combination of parts hereinafter more particularly de scribed and claimed.

In the accompanying drawing forming part of this specification, Fig. 1 is a side elevation of my improved sound box, Fig. 2 is a section taken on the line 22 01"- Fig. 1; Fig. 3 is a side elevation of the sound board when removed from the sound box; Fig. 4 is a side elevation of one of the spider elements'for supporting the sound board in the sound box; Fig. 5 is a section of a detail showing the construct-ion by which the sound board is removably secured in the sound box, and Fig. 6 is a plan of the needle or stylus support which assists in transmitting the vibrations of the needle or stylus to the sound diaphragms.

More particularly my invention relates to that classs of sound boxes which employs a plurality of sound diaphragms whereby greater sensitiveness and louder reproduction of sound is accomplished. In the exemplification of my invention illustrated by the drawing, two parallel sound diaphragms l0 and 11 are clamped securely in a rigid circular casing 12, said diaphragms being spaced apart to form a sound chamber A within the structure which is connected With a duct in the neck piece-13 on the casing. This neck piece is adapted to bejoined to the usualtone arm of a sound reproducing machine, not illustrated, in any convenient manner. Arranged within the sound chamber is a sound boa-rd B, which is positioned parallelwith and centrally between the two diaphragms said sound board being less in diameter than the inner diameter of the casing 12. The sound board and sound dia- WALTER srorroa'rrr, or sa PAUL, MINNESOTA. I

phragms areheld rigid in"the positionstated in thejfollowin'g manner." .A pair of circularspider fraii'iesle and 15 similar in construction and formed withfshoulder pieces 16 on-their innerends engaging over the' periphery of the sound board's have their outer ends 17 seated in pairs of ring collars 18 and 19 made out oit'fhard rubber o'r'any other suitable material" which fitclosely" within the circular casing12." The sound dia'phragms IOj'and ll rest with theiredg'es between these rings and" in turn are heldirrfl wardly by a pair of retaining rings 20 and i 21', threaded into the casing 12. "Int-his manner the sound diaphragms and sound board are all clamped inwardly under tension most effectively and in a simple manner. Poised on knife edges 25 and 26 which are arranged in the same plane occupied by the sound board is the needle or stylus point needle or stylus 28 in a socket29, said socket support 27, which'removably supports the being formed on the lower side of said. support and said needle or stylus being detach ably secured in the usual manner in said socket by a thumb screw 30. Connected with the needle or stylus support 27 are a pair,

of sound vibration transmitting girders 3'7 and 38, the outer ends of Which are secured in the usual manner to the centralportions of the two sound diaphragms l0, and 11 there being one bar for each diaphragm out of contact with the. casing 12. The needle or stylus support is held poised upon'the knife edges 25 and 26 undertens'ion bymeans of the springs 82 and adjusting screws 31. These screws 31 pass freely through the springs and the needle or stylus support and are secured in the lower portion of the casing 12 in the usual manner. By this con- I struction the needle or stylus support is free to vibrate as the needle or stylus travels in the sound record groove and to transmit the sound vibrations caused by the sound rec-- 0rd groove to the'sound diaphragms, said sound reproduction being greatly amplified by the use of two sound diaphragms. This sound which is produced in thesound chamber within the sound box is' improved in quality by the use of the sound board B, said sound board vibrating in synchronism with the sound ldiaphragms and producing finer tone quality in the duct leading from the sound chamber. The spaces betweenthe diaphragms: and adjacent sides of the sound board forming the sound chamber A are to usesother than those above set "forth within the scope ofthe lfQllOWll lg claini.

Having described niy invention, what I clainias new and desire to protect by Letters Patent is I A sound box for sound reproducing niachines, comprising, a cylindricalv casing forming an enclosure having a sound trans- IniSSlOiliClilCt in its side, a pair of substantially parallel sound reproducing diaphrag ns' in and combining with said casing to form a single sound chamber" connected with said duct, a sound board in'an'd of smaller d1- a-in'et'er than the bore of said chamber and positioned actively between said diaphragins,

a pair of spider framesupports for holding said board'spaced from and between said diaphragins and distanced inwardly ironi theside attenuating so that free passage of air at the circu nference ot' said board is permitted throL'ighIt-he spider franies, nonvibrant rings fit-ted intosaid casing'for seating the outer'en dsio'i' said spider frames and diaphragins in said casingwithout readily coii'ducting'souiid Vibrations, means for clamping said fr-allies, diaphragins and rings tightlyin said casing and yibration creating means associated with said diaph'ragms.

Signed at Std Paul, in the county of Ramsey and State o'f'l'vlinnesota, this 2nd day of October, 1919.

WALTER srori on'ru. 

